Villagers near the factory in Wenchuan county – the area worst hit by the disaster – have told the Guardian their health and crops have been damaged by airborne “white flake” pollution that falls and then covers the soil.

Though more than a year has passed since the quake killed 68,000 people and destroyed millions of homes on 12 May 2008, many residents still live in tents.

The local government has put a priority on rebuilding the economy, partly through the more than five-fold expansion of the Aba Aluminium production line owned by Bosai Corporation – one of Sichuan’s biggest exporters. This provides much-needed jobs in the disaster area, but they come at a heavy environmental price, according to nearby residents who complain their harvests have collapsed because of contamination.

“The expansion of the aluminium factory has really affected our lives. I used to grow vegetables and walnuts, but the pollution has ruined the plants and trees,” a local woman told the Guardian by telephone. “The powder from the plant floats in the air, and leaves a coating of white sediment on the ground.”